1. Technical Field of the Invention
The present invention relates generally to starters for staring engines. More particularly, the invention relates to a starter for starting an engine, which includes an electromagnetic switch that has a protective cover for protecting terminals of the electromagnetic switch.
2. Description of the Related Art
Japanese Patent Application Publication No. 2006-286258, an English equivalent of which is U.S. Pat. No. 7,116,196 B1, discloses a starter electromagnetic switch that includes a movable contact, a pair of fixed contacts, a switch cover (or contact cover), a switch coil (or excitation coil), a switch terminal bolt, and a motor terminal. The switch cover covers the movable contact and has the fixed contacts fixed thereto facing the movable contact. The switch terminal bolt is fixed to the switch cover to supply electric power to the switch coil. The switch terminal bolt has a head portion insert-molded in the switch cover and a shaft portion that protrudes outside the switch cover so as to be electrically connected to a battery. The motor terminal is also fixed to the switch cover to supply electric power to a starter motor via the movable and fixed contacts. The motor terminal has a head portion, which is integrally formed with one of the fixed contacts, and a shaft portion that protrudes outside the switch cover and is electrically connected to the starter motor.
With the above configuration, it is possible to make electrical connection between the shaft portion of the switch terminal bolt and the battery and between the shaft portion of the motor terminal and the starter motor by using low-cost versatile round terminals. However, at the same time, since both the shaft portions of the switch terminal bolt and motor terminal are exposed to external, the shaft portions are vulnerable to water damage. Consequently, it is difficult to secure reliable electric connection between the shaft portion of the switch terminal bolt and the battery and between the shaft portion of the motor terminal and the starter motor.
Japanese Patent Application Publication No. 2003-208840, an English equivalent of which is U.S. Pat. No. 6,930,576 B1, discloses a starter electromagnetic switch that includes a movable contact, a pair of fixed contacts, a molded-cap (or contact cover), an excitation coil, a current-supply terminal (or excitation coil terminal), and a motor terminal. The molded cap covers the movable contact and has the fixed contacts fixed thereto facing the movable contact. The current-supply terminal is fixed to the molded cap to supply electric current to the excitation coil. The current-supply terminal has one end, which is located inside the molded cap and electrically connected to the excitation coil, and the other end that protrudes outside the molded cap and is held in a connector portion of the molded cap. The motor terminal is also fixed to the molded cap to supply electric power to a starter motor via the movable and fixed contacts. The motor terminal has a head portion, which is integrally formed with one of the fixed contacts, and a shaft portion that protrudes outside the molded cap and is electrically connected to the starter motor.
With the above configuration, since the shaft portion of the current-supply terminal is enclosed by the connector portion of the molded cap, it can be protected from water damage. However, at the same time, different users of engine starters have different requirements for the shapes and sizes of the connector portion and current-supply terminal. Accordingly, the connector portion and current-supply terminal cannot be standardized, thus making it difficult to minimize the manufacturing cost. Moreover, since the shaft portion of the motor terminal is exposed to external, it cannot be protected from water damage.